Method of making a coil



July 2, 1963 0. w. LAVIANA METHOD OF MAKING A COIL 2 Sheets-Sheet 2Original Filed Sept. 11, 1956 Fig.9

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Fig/2 INVENTOR. Donald W. Law'ana His Attorney nite States Thisinvention pertains to an electrical coil assembly, and particularly toan improved coil construction and method of making the same. Thisapplication is a division of Serial No. 609,274 filed September 11,1956, now Patent No. 2,992,370.

Heretofore, most electric coils for solenoids, or relays, have beenconstructed with a separate terminal block assembly which is taped tothe winding. The ends of the winding are Wrapped around the terminalsand, thereafter, individually soldered to eflect the desired mechanicaland electrical connection. The present invention re lates to a coilassembly wherein the terminals are secured to tabs on the end flanges ofthe spool, or bobbin, about which the coil is wound. Consequently, theends of the winding can be directly secured to the terminals by a dipsoldering process. Thereafter, the end tabs are bent inwardly andsecured to the winding by tape. Accordingly, among my objects are theprovision of a method of assembling an electric coil having the uniquespool and terminal assembly of this invention.

The aforementioned and other objects are accomplished in the presentinvention by attaching preformed terminals, having portions disposed atan angle to each other, to radially extending tabs on the end flanges ofa spool. Specifically, in one embodiment, the spool, or bobbin, iscomposed of insulating material and includes a core having a flange ateach end. Each flange has a radially extending tab that extends beyondthe periphery of the coil assembly before and immediately after the wireis wound on the core. The end flanges are notched adjacent to the edgesof the tab, and each ta-b may be formed with a bend-line to facilitatefolding of the tabs inwardly after the ends of the Winding are attachedto the initially radially extending terminal portions. Thereafter, tapeis wound around the tabs in the customary manner to provide insulationfor the exposed portion of the winding and to provide the necessarymechanical strength to produce a firm coil assembly.

In coil designs for high voltage applications, a thin piece ofinsulation conforming approximately to the curvature of the coil may beinserted between the radially extending tabs sothat it will lieimmediately between the terminals and the Winding after the tabs havebeen bent inwardly to engage the winding. Moreover, in cases Where thespool prohibits the installation of the terminals in alignment with eachother, the tabs may be displaced angularly with respect to each other sothat when the tabs have been bent inwardly towards the windings, theterminals and tabs will be circumferentially spaced about the Winding.In addition, a second flange of dielectric material located outwardly ofthe flange having the tabs thereon, may be provided to assure properinsulation characteristics at the point where the notches are formed inthe end flanges having the terminals.

In some instances, the spool is designed to have wound therearound twocoil assemblies, in which instance each end flange is formed with a pairof angularly spaced radially extending tabs to which terminals areattached. In a further modification, the end flanges of the spool may beformed with a pair of angularly spaced, radially extending tabs and aterminal may be attached to only one of tent ice

the tabs. In this arrangement, the tab without the terminal on one endflange is bent inwardly to engage the winding of the coil, and the tabhaving the terminal attached thereto is bent, or superimposed, on thistab to provide the necessary insulation between the Winding and theterminal. In all modifications, the core of the spool is formed with apair of diametrically opposed notches adjacent each end which receiveradially extending tangs formed on the end of the flanges. The extendingportions of the core are thereafter spun around the flanges to form thebobbin, or spool assembly.

The method of assembling the coil construction of this inventionincludes the steps of attaching the terminals to the tabs on the endflanges of the spool; winding one end of the Wire around the extendedportions of one of the terminals; winding the wire about the core whichis mounted on a spindle or other rotating element, in the usual manner;wrapping the other end of the wire around the extended portion of theother terminal; dipping the radially extending terminal portions withthe coil ends wrapped therearound into a soldering pot to obtain a goodmechanical and electrical connection; bending the tabs having theterminals attached thereto inwardly through an angle of substantially90; and taping the tabs and terminal portions to the winding in thecustomary manner.

The completed coil assembly has terminal portions extending radiallyfrom the winding for connecting to an external circuit. Moreover, thecoil assembly is extremely rugged, and it has been found thatsubstantial manufacturing economies can be realized by assembling coilsin the manner taught by this invention.

Further objects and advantages of the present invention Will be apparentfrom the following description, reference being bad to the accompanyingdrawings wherein preferred embodiments of the present invention areclearly shown.

In the drawings:

FIGURE 1 is a view, in elevation, of the spool and terminal assembly ofthis invention.

FIGURE 2 is an end view taken in the direction of arrow 2 of FIGURE 1.

FIGURE 3 is a view, partly in section and partly in elevation, of thespool having a winding thereon.

FIGURE 4 is a view, partly in section and partly in elevation, taken inthe direction of arrow 4 of FIGURE 3.

FIGURE 5 is a fragmentary view illustrating the manner in which the endsof the winding are connected to the terminals by dip soldering.

FIGURE 6 is a view in elevation of the coil after the terminal tabs havebeen soldered to the windings and after the tabs have been bent inwardlythroughout the angle of substantially FIGURE 7 is a view of thecompleted coil assembly of the first embodiment of this inventionwherein the terminal tabs are taped to the winding.

FIGURE 8 is a longitudinal sectional view of a coil constructedaccording to the second embodiment of this invention.

FIGURE 9 is an end view, in elevation, of an end flange used in the coilconstruction of FIGURE 8.

FIGURE 10 is an end view, in elevation, of a modified end flangeconstructed according to the third embodiment of this invention.

FIGURE 11 is a longitudinal sectional view of a coil construction inaccordance with the fourth embodiment of this invention.

FIGURE 12 is an end view, in elevation, of the spool, or bobbin,assembly used in the coil construction of FIGURE 11.

FIGURE 13 is an end view of the coil construction 3 of FIGURE 11 takenin the direction of arrow 13 of FIGURE 11.

With particular reference to FIGURE 1, the coil assembly of thisinvention includes a unique spool and terminal assembly designatedgenerally by the numeral 10. The spool and terminal assembly comprises acore 12 of insulating material having diametrically opposed notchesadjacent each end thereof. As shown in FIG- URE 1, the core 12 receivesa pair of end flanges 14 and 16 of insulating material having a centralaperture with a pair of diametrically opposed inwardly extending tangsthereon. The notches in the core 12 are depicted by the numeral 13 inthe drawings. After the end flanges 14 and 16 are positioned over theends of the core 12, the extending ends of the core 12 are spun over toproduce the core assembly The end flanges 14 and 16 are also formed withradially extending tabs 18 and 20, respectively. As seen in FIGURE 2.,tab 18 on flange 14 is formed with a bend-line 22, and the periphery ofthe flange 14 is notched at 24 and 26- adjacent the sides of the tab 18.The tab 20 on the end of the flange 16 is of identical construction.

A terminal connector 28 having portions '30 and 32 located atsubstantially right angles to each other, is attached to the tab 18 bymeans of the rivet 34. The terminal portion 30 which is initiallylocated radially to the core 12, has a notch 36 in one edge thereofwithin which one end of the winding, to be described, is wrapped around,The portion 32 of the terminal 28 is formed with an opening 37 to whichan external circuit can be connected.

A terminal 38 of identical construction to the terminal 28 is attachedto the tab 20 of the flange 16 by means of a rivet 44. The terminal 28,thus, includes portions 40 and 42 located at substantially right anglesto each other, the portion 41' having a notch 46 and receiving the otherend of the winding. The portion 42 has a hole 47 therein for connectingto an external circuit. The terminals 28 and 33 are preformed into theshape shown in FIGURES l and 2.

After the terminals 28 and 33 are attached to the tabs on the spool andflanges, a winding 48, as shown in FIG URES 3 and 4, is wound around thecore 12. One end 50 of the winding is wrapped around the portion 30 ofthe terminal wtihin the slot 36 before the coil is wound on the core.The other end 52 of the winding is wound around the portion 40 of theterminal '38 in a similar manner after the coil is wound on the core.The coil may be wound on the core in a conventional manner by placingthe spool on a spindle, or other rotating element. Thereafter, the endsof the terminal portions 30 and 40 having the wires 50 and 52 wrappedthereabout are immersed in a pot of molten solder, as indicated bynumeral 54 so as to obtain a good mechanical and electrical connectionbetween the terminals and the ends of the windings.

After the soldering operation, the tabs 18 and 20 are folded, or bent,throughout substantially 90, and into engagement with the winding 48 asshown in FIGURE 6. The tabs 18 and 20 can be readily folded over sincethe end flanges 14 and 16 are formed with bend-lines, as aforementioned.Thereafter, the tabs 18 and 20 are secured :to the windings byinsulating tape 56, as shown in FIGURE 7, to complete the coil assembly.

With reference to FIGURE 8, a modified coil construction is shownwherein a second insulating flange is interposed between the end of thecore and the flange having the radially extending tab thereon. Thisflange is depicted by the numeral 60 and is incorporated to provide theproper insulation characteristics at the point where the notches areformed in the end flange 62 adjacent the radially extending tab. Asimilar insulating end flange 64 is positioned outwardly of the endflange 66 at the other end of the core 12. In the embodiment of FIGURES8 and 9, the end flanges 562 and 66 may have their radially extendingtabs angularly spaced as depicted in FIGURE 9. Thus, the radiallyextending tab 68 on the end flange 62 is angularly spaced from theradially extending tab 70 on the end flange 66. This arrangement isnecessary where the length of the core 12 is insufficient to accommodatethe tabs 68 and 70 in alignment. The terminals 72 and 74 attached to thetabs 60 and 70 are the same as the terminals hereinbefore described. Inthe FIGURE 8 embodiment, a piece of dielectric material 76, whichconforms to the winding 78, is interposed between the tabs 68 and 70 andthe winding'to insulate the terminals from the winding. Thereafter,insulating tape is wound around the coil assembly to hold the terminalsin position.

With particular reference to FIGURE '10, a modified end flange for thecore 12 is shown. In the modified end flange, depicted by numeral 82, apair of angularly spaced, radially extending tabs 84 and 86 are formedon the flange 82. This type of end flange is utilized where two coilsare wound on the core. In both FIGURES 9 and 10, the inwardly extendingtangs 87, for engaging the notches in the cylindrical core 12 areclearly shown.

With particular reference to FIGURES 11 through 13, a furthermodification of the coil assembly of this invention is shown. In thismodification as shown on FIGURE 12, each end flange 88 is formed with apair of angularly spaced, radially extending tabs 90' and 92. A terminal94 of the type hereinbefore described is secured to the tab 92. However,a terminal is not attached to the radially extending tab 90. The endflange 96 of the opposite end of the core is likewise formed with a pairof angularly spaced radially extending tabs 98 and 100. The tabs 100 and90 are of greater radial extent than the tabs 92 and 98. In addition, aterminal 102 is attached to the tab 98. The tab 100* is aligned with thetab 92 on the end flange 88, while the tab 90 on the end flange 88 isaligned with the tab 98 on the end flange 96. Thus, after the coil 104is wound around the core, and the ends of the winding 104 are attachedto the terminals 94 and 102, and are affix-ed thereto by dip soldering,the tab 100 is bent through 90 and there after the tab 92 is bent on thetop of the tab 100. In a similar manner, the tab 90 is bent after whichthe tab 98 is bent to lie over the tab 90. Thus, the auxiliary tabs 90'and 100 space the tabs 94 and 102 from the winding 104 so as to providethe necessary insulation therebetween. The coil assembly is thencompleted as aforedescribed by winding tape 106 about the winding tosecure the terminals in position.

In the completed coil assembly, the terminal portions which extendradially from the Winding facilitate the connection of the winding withan external circuit.

Moreover, by attaching the terminals to tabs which are integral with theend flanges of the spool, a more rigid coil assembly can be produced. Inaddition, the manufaoturing economies resulting from using the process'of manufacturing coil assemblies as set forth in this invention greatlyreduce the cost of the completed coil assemblies.

While the embodiments of the present invention as herein disclosed,constitute preferred forms, it is to be understood that other formsmight be adapted.

What is claimed is as follows:

1. A method of making a coil having a spool with a core and flanges ateach end, each flange having an outwardly extending tab to which aterminal having portions extending axially and radially of the core isattached, comprising the steps of, winding a wire coil around the core,wrapping the ends of the wire coil around the radially extendingportions of the terminals, dipping only the radially extending portionsof the terminals in molten solder, bending the tabs inwardly to overlaythe wire coil, and securing the tabs to the wire coil.

2. The method of making a coil having a spool with a core and flanges ateach end, each flange having an outwardly extending tab to which aterminal is attached having portions arranged normal to each other,comprising the steps of Winding a wire coil around said spool, securingopposite ends of said coil to the portions of said terminals alignedwith said tabs, dipping only the last recited terminal portions inmolten solder to permanently attach the ends of the wire coil theretobending the tabs and said last recited terminal portions into engagementwith the coil, and securing the tabs to the coil.

3. The method of making a coil having a spool with a core and flanges ateach end, each flange having a pair of spaced tabs thereon of differentlengths, a terminal attached to each shorter tab, the shorter and longertabs on the opposed end flanges being in alignment with each other,comprising the steps of, winding a wire coi-l around the core, securingthe ends of the wire coil to said terminals, dipping said terminals inmolten solder to permanently attach the ends of the wire coil thereto,bending the longer tabs inwardly into engagement with the coil, bendingthe shorter tabs inwardly to overlay said longer tabs, and securing thetabs to the coil.

4. The method of making a coil having a spool with a core and flanges ateach end, each flange having a radially extending tab, comprising thesteps of, attaching a terminal to each radially extending tab, eachterminal having portions arranged normal to each other, Winding a wirecoil around said core, securing the ends of the wire coil to theportions :of said terminals aligned with said radially extending tabs,dipping only the last recited terminal portions in molten solder topermanently attach the ends of the wire coil thereto, and bending thetabs inwardly into engagement with the coil so that the other portionsof said terminals extend radially outward from said coil.

5. The method of making a coil having a spool with a core and flanges ateach end, each flange having a radially extending tab, comprising thesteps of, attaching a terminal to each radially extending tab, eachterminal having portions arranged normal to each other, winding a wirecoil around said core, securing the ends of the Wire coil to theportions of said terminals aligned with said radially extending tabs,dipping only the last recited terminal portions in molten solder topermanently attach the ends of the wire coil thereto, bending the tabsinwardly into engagement with the coil so that the other portions ofsaid terminals extend radially outward from said coil, and securing saidtabs to the wire coil.

References Cited in the file of this patent UNITED STATES PATENTS1,751,854 Da Costa Mar. 25, 1930 1,815,212 Ogg July 21, 1931 1,968,600Driftmeyer July 31, 1934 2,184,342 Grupe et al. Dec. 26, 1939 2,214,151Wagar Sept. 10, 1940 2,471,869 Gebel Mar. 14, 1946 2,486,751 McMichaelNov. 1, 1949 2,488,468 Dinion Nov. 15, 1949 2,633,481 Meeks Mar. 31,1953 2,649,558 Franz Aug. 18, 1953

1. A METHOD OF MAKING A COIL HAVING A SPOOL WITH A CORE AND FLANGES ATEACH END, EACH FLANGE HAVING AN OUTWARDLY EXTENDING TAB TO WHICH ATERMINAL HAVING PORTIONS EXTENDING AXIALLY AND RADIALLY OF THE CORE ISATTACHED, COMPRISING THE STEPS OF, WINDING A WIRE COIL AROUND THE CORE,WRAPPING THE ENDS OF THE WIRE COIL AROUND THE RADIALLY EXTENDINGPORTIONS OF THE TERMIALS, DIPPING ONLY THE RADIALLY EXTENDING PORTIONSOF THE TERMINALS IN MOLTEN SOLDER, BENDING THE TABS INWARDLY TO OVERLAYTHE WIRE COIL, AND SECURING THE TABS TO THE WIRE COIL.